Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
Semiconductor devices may include core devices and input/output devices. The core devices may be used to perform the functions of a chip, and the input/output devices may be used to communicate with external circuits in other chips. Although existing manufacturing processes for these semiconductor devices have generally been adequate for their intended purposes, as device scaling-down continues, they have not been entirely satisfactory in all respects.